1. Field of the Disclosure
The present disclosure relates to a display device including a touch panel, and more particularly, to a display device including a touch panel having a passivation layer on an edge portion of a rear surface thereof and a method of fabricating the display device.
2. Discussion of the Related Art
As the information age progresses, display devices processing and displaying a large amount of information have been rapidly developed. Specifically, various flat panel displays (FPDs) such as a liquid crystal display (LCD) device, a plasma display panel (PDP) device, an organic light emitting diode (OLED) display devices and a field emission display (FED) device having a superior performance with a thin profile, a light weight, and a low power consumption have substituted for a cathode ray tube (CRT).
Recently, a touch display device, referred to as a touch screen, where a touch panel is attached to a display panel has been widely used. The touch display device is used as an output means for displaying an image and is also used as an input means for receiving a command of a user by touch of a portion of the image. The touch panel is classified into a resistive type, a capacitive type, an infrared type and an ultrasonic type.
When a user watches the image displayed by the display panel and touches the touch panel, the touch panel detects position information of the touched portion and perceives the user's command by comparing the position information of the touched portion and the position information of the image.
The touch display device may be fabricated by attaching a separate touch panel to a display panel, or may be fabricated as an integrated device by forming a touch panel on a substrate for a display panel.
A structure of a touch display device will be illustrated with reference to a drawing hereinafter.
FIG. 1 is a cross-sectional view showing a glass-film-film (GFF) type touch display device according to the related art.
In FIG. 1, a GFF type touch display device 10 according to the related art includes a display panel 20 displaying an image and a touch panel 30 over the display panel 20. The touch panel 30 detects position information corresponding to a touch point by a user.
The touch panel 30 includes a cover glass 40, and first and second touch films 50 and 60 sequentially disposed under the cover glass 40. A first adhesive layer 70 is formed between the cover glass 40 and the first touch film 50 so that the first touch film 50 can be attached to the cover glass 40 by the first adhesive layer 70. A second adhesive layer 72 is formed between the first and second touch films 50 and 60 so that the second touch film 60 can be attached to the first touch film 50 by the second adhesive layer 72. In addition, a third adhesive layer 74 is formed between the second touch film 60 and the display panel 20 so that the display panel 20 can be attached to the second touch film 60 by the third adhesive layer 74.
A plurality of first lines 52 are formed on the first touch film 50 and a plurality of second lines 62 are formed on the second touch film 60. The plurality of first lines 52 may transmit a driving signal and the plurality of second lines 62 may receive a detecting signal. In addition, a crossing portion of the plurality of first lines 52 and the plurality of second lines 62 constitute a capacitor having a variable capacitance according to touch of the user.
Although the GFF type touch display device 10 has been widely used, total thickness and fabrication cost of the GFF type touch display device 10 increase due to the first and second touch films 50 and 60 and the second adhesive layer 72 attaching the first and second touch films 50 and 60.
For the purpose of reducing the total thickness and the fabrication cost, a glass-film-two (GF2) type touch display device using a single touch film has been suggested and a structure of a GF2 type touch display device will be illustrated with reference to a drawing hereinafter.
FIG. 2 is a cross-sectional view showing a GF2 type touch display device according to the related art.
In FIG. 2, a GF2 type touch display device 110 according to the related art includes a display panel 120 displaying an image and a touch panel 130 over the display panel 120. The touch panel 130 detects position information corresponding to a touch point by a user.
The touch panel 130 includes a cover glass 140, a touch films 150 under the cover glass 140 and a protecting film 160 under the touch film 150. A first adhesive layer 170 is formed between the cover glass 140 and the touch film 150 so that the touch film 150 can be attached to the cover glass 140 by the first adhesive layer 170. A second adhesive layer 172 is formed between the protecting film 160 and the display panel 120 so that the display panel 120 can be attached to the protecting film 160 by the second adhesive layer 172.
A plurality of first lines 152 are formed on an upper surface of the touch film 150 and a plurality of second lines 154 are formed on a lower surface of the touch film 150. The plurality of first lines 152 may transmit a driving signal and the plurality of second lines 154 may receive a detecting signal. In addition, a crossing portion of the plurality of first lines 152 and the plurality of second lines 154 constitute a capacitor having a variable capacitance according to touch of the user.
The protecting film 160 under the touch film 150 may protect the plurality of second lines 154 on the lower surface of the touch film 150. Since the touch film 150 is formed to have a size greater than a size of the display panel 120, an edge portion of the touch film 150 may constitute an exposing area A exposed outside the display panel 120. As a result, the plurality of second lines 154 in the exposing area A on the lower surface of the touch film 150 are exposed outside the display panel 120 and are corroded by moisture or contaminant in the atmospheric air to cause electrical opening.
For the purpose of preventing the electric open, the protecting film 160 is formed to cover the whole lower surface of the touch film 150. For example, the protecting film 160 may be formed of polyethylene terephthalate (PET) and may have a thickness equal to greater than about 0.1 mm.
However, since total thickness and fabrication cost increase due to the protecting film 160, comparative advantages of the GF2 type touch display device 110 as compared with the GFF type touch display device 10 (of FIG. 1) in thickness and fabrication cost are reduced.